Breather system and roof for sealed storage structure



March 1954 LE ROY M. OSBORNE 3,

BREATHER SYSTEM AND ROOF FOR SEALED STORAGE STRUCTURE Filed Jan. 6. 1960 2 Sheets-Sheet 1 INVENTOR.

LeRoy M. Osborne MdA M Oittorneys March 1964 LE ROY M. OSBORNE 3,122,935

BREATHER SYSTEM AND ROOF FOR SEALED STORAGE STRUCTURE Filed Jan. 6, 1960 2 Sheets-Sheet 2 INVENTOR. LeRoy M. Osborne fitter/regs United States Patent 3,122,985 BREATTER SYSTEM AND RQGF FOR SEALED STORAGE STRUCTURE Le Roy M. Gshorne, Kankakee, 111., assignor, by mesne assignments, to A. 0. Smith Harvesters Products, Inc, Kankakee, EL, a corporation of Delaware Filed Jan. 6, 1960, Ser. No. 850 Claims. (Cl. 99235) This invention relates to an improved air tight storage structure and particularly to a storage structure having a flexible bag member which acts both as a roof and an air tight seal for the structure.

It has been generally observed that a storage structure such as a silo is subjected to widely varying temperature changes which in turn substantially effect internal struc ture pressures. This is especially true in air tight silos. The temperature md consequent internal pressure changes are due primarily to normal daily temperature fluctuations and seasonal variations. Under conditions causing a decrease in internal structure pressure to a point below atmospheric pressure there is a tendency for outside air to flow into the structure in order to establish an equilization of the pressures. Conversely, when conditions cause a pressure increase in the structure in excess of atmospheric pressure there is a tendency for the gases to flow out of the structure until such time as the pressure within the structure equals that of the atmosphere outside.

The cells of plants stored in a silo generally continue to respire and produce an appreciable amount of gases including large quantities of carbon dioxide. If carbon dioxide can be retained within the silo so that air is excluded, the process of fermentation will continue without spoilage of the silage. Should, however, carbon dioxide escape and a substantial amount of air replace the lost gas, the free oxygen will tend to promote mold growth in the silage and enhance spoilage.

In the present invention a flexible balloon-like bag is employed to provide a roof for a storage structure such as a silo. The bag functions in a manner that will prevent escape of internal gases from the structure and entrance of outside atmosphere into the storage structure. A decrease in internal pressure will cause an expansion of the bag while the bag will respond to a pressure increase by contracting.

The flexible bag is located in the top of the storage structure in a manner whereby inflation to a determined ressure will force the side of the bag securely against the internal wall of the storage structure providing an air tight seal.

Two concentric flexible bags may be employed in order to permit loading of the storage structure through the roof at any time. This can be accomplished by deflating the inner bag, loading the structure through the resultant opening, and on completion of the loading operation reinflating the bag to a pressure sufficient to force the walls of the inner bag securely against the walls of the outer bag thereby providing an air tight seal.

This flexible bag form of roof will function to prevent structure distortion due to pressure changes which would otherwise occur if an air tight storage structure were sealed without some type of breathing means.

A roof of this type will also have great commercial utility in being cheaper to manufacture and easier to install and maintain than a rigid roof.

Other objects and advantages of the invention will appear in the course of the following description.

The drawings furnished herewith illustrate the best modes presently contemplated for carrying out the invention as hereinafter set forth.

, 3,l22,85 Patented Mar. 3, 196 1- "ice FIGURE 1 is a vertical sectional view of a storage structure, with parts broken away, showing the flexible roof forming bag in sealed relation;

FIGURE 2 is a top plan view of a storage structure showing the flexible, roof-forming bag in sealed relation;

FIGURE 3 is an enlarged vertical section of a modified form of the invention and showing an alternate form of the flexible bag.

FIGURE 4 is an enlarged vertical section of the upper portion of the storage structure illustrating in sealed relation a second modified form of the flexible, roof-forming bag.

The drawings illustrate a cylindrical storage structure, such as a silo, adapted to contain silage or like material. The structure comprises a plurality of generally curved plates 1 joined at joints 2. Joints 2. are provided with a sealing material which is impervious to air and moisture. The plates 1 may be formed from steel and have a coating or lining of ceramic enamel fused to both surfaces. The coating will act to protect the structure from deterioration due to weathering and the corrosive eflects of the stored material.

The silo is secured to a concrete foundation 3 which also acts as a floor. A bottom unloading apparatus 4 similar in structure and function to that described in the Tiedemann Patent 2,635,770 is disposed in the bottom of the silo. The unloader 4 acts at the bottom of the silo to dislodge, cut and remove the material stored therein. Removal of stored material from the bottom of the silo causes the remainder to gravitate upon the unloader 4 thereby facilitating continuous removal.

An inflatable flexible bag 5, impervious to air and liquids, is disposed in the open top of the silo. The bag 5, when inflated to a sufiicient pressure, has a generally cylindrical side wall 6, a convex top wall 7 and a concave bottom wall 8. The pressure acts to force side wall 6 securely against the uppermost portion of the internal silo wall formed by plates 1 to provide an air-tight seal of the silo.

The top wall 7 and the upper portion of side wall 6 of bag 5 upon inflation generally protrude above the open top of the silo functioning as a silo roof and the bottom wall 8 of the bag remains substantially below the open top of the silo.

Bag 5 is provided with an annular apron like member 9 extending downwardly and outwardly from the uppermost peripheral edge of side wall 6. A plurality of spaced grommets 10 or other suitable fastening means are disposed adjacent the peripheral edge of apron member 9.

Cooperating with the grommets 10 are a plurality of spaced hook members 11 bolted or attached by other suitable means to the external surface of plates 1; ad-

jacent the uppermost peripheral edge of the silo.

Apron member 9 is fastened to the hook members 11 by grommets 1t) and acts to secure and maintain the desired position of bag 5 in the silo top. Convex top wall 7 sheds water and in cooperation with apron 9 also prevents moisture and foreign particles from filtering down between side wall 6 and the internal surface of the silo.

As is best seen in FIGURE 1, a conduit 12 is attached to the bag and extends to a compressor 13 or other suitable inflating equipment. A pressure regulator 14 is provided in conduit 12 to maintain a predetermined pressure in bag 5.

Pressure changes in the silo due to temperature variations, removal of stored material or formation of gases within the silo are reflected by expansion and contraction of the flexible bag 5. A reduction in internal silo pressure will cause the bag to expand while conversely an increase in internal silo pressure will cause a contraction of the flexible bag as it acts to equalize internal and external 3 pressures. Throughout these fluctuations a sufficient pressure is provided within the bag and silo. Use of a flexible bag also eliminates the danger of structural distortion which frequently accompanies pressure changes in rigid air tight storage structures.

FIGURE 3 illustrates a variation in the mode of attachment and formation of the flexible roof for the silo. In this embodiment an annular angle iron 15 is attached adjacent the uppermost outer peripheral edge of the silo wall by a plurality of bolts 1.6. A pair of generally circular flexible members 17 and 13 are disposed in the open top of the silo and the peripheral edge portions of flexible members 17 and 18 are secured to the upper surface of angle iron 15 by a retaining ring 19 and bolts 20.

An annular gasket 21 of a suitable resilient material is disposed between the peripheral edge portions of the members 17 and 18 and serves to cushion the joint. This construction provides an air tight seal at the point of contact of members 17 and 18 with gasket 21 and forms a flexible bag similar to bag having the same functions and advantages as bag 5. A conduit 22 is attached to upper member 18 to accomplish inflation as in the case of bag 5. A compressor and regulator similar to that seen in FIGURE 1 may be employed.

Upon inflation of the bag formed by members 17 and 18, lower member 17, as may be seen in FIG. 2, has a generally cylindrical shape with a concave bottom while upper member 18 is convex and acts as a roof for member 17.

FIGURE 4 illustrates another method contemplated for carrying out the invention. An inflatable flexible bag 23 having a generally donut shape is disposed in a silo similar to that illustrated in FIGURE 1 and in a manner similar to the disposition of bag 5. A conduit 24 connects the bag 23 and inflating and regulating means similar to that in FIGURE 1 are employed to accomplish and maintain inflation. Upon inflation, the central opening 25 in bag 23 permits loading of the silo. When the loading operation has been completed, a second inflatable flexible bag 26 is disposed in opening 25. A conduit 27 is attached between bag 26 and an inflating and regulating means similar to that seen in FIGURE 1. Upon inflation, bag 26 acts to firmly contact the internal peripheral wall of bag 23 bordering opening 25 thereby effecting an airtight seal of the opening.

A generally circular flexible sheet 28 having a series of grommets or other suitable fastening means 29 adjacent its peripheral edge is disposed above bags 23 and 26 following the loading operation. Sheet 28 is secured to the silo by attachment of grommets 2 to hook members 30 similar to hooks 10. The secured sheet 28 acts to maintain proper positioning and alignment of bags 23 and 26 and prevents moisture and foreign particles from filtering down between the silo and bags 23 and 26.

The structure of this embodiment, as well as that illustrated in FIGURE 1, will serve as a roof for a storage structure, act as a pressure equalizer, prevent structural distortion, and in addition will facilitate top loading of the silo.

Various modes of carrying out the invention are contemplated as being Within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. In a storage structure having an internal surface impervious to air and moisture and having an open top, an annular flexible bag disposed within the open top of said storage structure with the external surface of said bag disposed in generally immobile engagement with the internal surface of the walls bordering the top opening of the storage structure and acting to provide a seal of the joint between the structure and the bag, a smaller second flexible bag removably disposed in the central opening of the annular bag whereby said second bag is removably disposed in engagement with the wall of said first bag bordering the central opening in said first bag and acts to complete the seal of the top opening of said structure and to render the interior of the storage structure air tight.

2. A storage structure, comprising a foundation, a hollow cylindrical member having an open top, said cylindrical member vertically mounted upon said foundation, said foundation and cylindrical member providing a storage container impervious to air and moisture and adapted to contain a stored material, a first inflated flexible bag of an annular shape defining outer and inner concentric generally cylindrical surfaces and having generally parallel upper and lower surfaces, said bag being disposed substantially inside the uppermost portion of said cylin: drical member bordering the open top whereby the outer cylindrical surface of said bag is disposed in generally immobile engagement with the inner wall of said cylindrical member providing an air tight seal of the annular joint, a conduit attached to said first bag, a second inflated flexible bag having a generally cylindrical shape 7 complementing the cylindrical central opening in said annular shaped first bag and removably disposed in the opening whereby the peripheral cylindrical surface of said second bag is disposed in removable engagement with the inner cylindrical surface of said annular bag providing an air tight seal of the annular joint and rendering the entire storage structure air tight, a conduit attached to said second bag, a generally circular flexible sheet member disposed above said flexible bags, means for attaching said sheet member to the cylindrical member, means connected to said conduits for inflating said bags, and means for regulating the pressure in said bags.

3. In a storage structure having an open extremity, an

inflatable flexible bag disposed substantially inside the open extremity and providing the sole enclosure for the open extremity, the outer peripheral surface of the bag bein in tight sealing engagement with the inner surface. of said structure bordering the open extremity to thereby substantially immobilize the peripheral surface of the bag with respect to the walls bordering the extremity and seal the storage structure, means for connecting the bag to the structure adjacent said open extremity to prevent axial movement of the bag with respect to said structure, means for inflating said bag, and pressure regulating means for maintaining a substantially constant internal pressure in the bag suflicient to maintain a uniform sealing force against the inner surface of said structure. 4. A storage structure, comprising a foundation, a

generally cylindrical hollow member having an open top vertically mounted on the foundation, said foundation and hollow member acting to provide a storage container im;

pervious to air and moisture, a flexible bag disposed in the open top of the hollow member and providing the V sole enclosure for said open top, a first portion of the bag being exposed above said open top of the member and a second portion being disposed within the member, the' first portion of the flexible bag being disposed for ex pansion from the open top of the hollow member to the elastic limit of the first portion of theflexible bag, said member to limit the inner and outer axial movement of,

the bag with respect to said member.

5. In a storage structure having an open extremity, a plurality of connecting elements disposed on the exterior of the storage structure and adjacent the open extremity thereof, an inflatable flexible bag disposed in the open extremity of the structure, the peripheral surface of said bag being in tight sealing contact with the inner wall of the storage structure bordering the open extremity thereof to thereby seal the open extremity of the storage structure, an apron-like member connected to and extending radialiy outwardly from the periphery of the flexible bag and covering the joint between the bag and the inner wall of the structure, and means for attaching the apron-like member to the connecting elements on the exterior or" the structure to thereby utilize the exterior of the structure adjacent the open extremity thereof to maintain the proper positioning and alignment of the bag and whereby the apron-like member acts to prevents the entrance of foreign matter into the storage structure at said joint.

References Cited in the file of this patent UNITED STATES PATENTS Patrick Sept. 10, Martin May 1, Wasserman Sept. 16, Martin June 30, Derringer Nov. 1, Lithun Oct. 28, Domitrovic June 2,

FOREIGN PATENTS Italy Ian. 8, Italy Oct. 13, Germany Mar. 24. 

4. A STORAGE STRUCTURE, COMPRISING A FOUNDATION, A GENERALLY CYLINDRICAL HOLLOW MEMBER HAVING AN OPEN TOP VERTICALLY MOUNTED ON THE FOUNDATION, SAID FOUNDATION AND HOLLOW MEMBER ACTING TO PROVIDE A STORAGE CONTAINER IMPERVIOUS TO AIR AND MOISTURE, A FLEXIBLE BAG DISPOSED IN THE OPEN TOP OF THE HOLLOW MEMBER AND PROVIDING THE SOLE ENCLOSURE FOR SAID OPEN TOP, A FIRST PORTION OF THE BAG BEING EXPOSED ABOVE SAID OPEN TOP OF THE MEMBER AND A SECOND PORTION BEING DISPOSED WITHIN THE MEMBER, THE FIRST PORTION OF THE FLEXIBLE BAG BEING DISPOSED FOR EXPANSION FROM THE OPEN TOP OF THE HOLLOW MEMBER TO THE ELASTIC LIMIT OF THE FIRST PORTION OF THE FLEXIBLE BAG, SAID BAG BEING DISPOSED IN SEALING RELATION WITH THE INNER CYLINDRICAL WALL OF SAID MEMBER OVER A SUBSTANTIAL VERTICAL DISTANCE, AND CONNECTING MEANS FOR CONNECTING THE PERIPHERAL PORTION OF THE BAG TO THE OUTER SURFACE OF THE HOLLOW MEMBER TO LIMIT THE INNER AND OUTER AXIAL MOVEMENT OF THE BAG WITH RESPECT TO SAID MEMBER. 